Dehydrator



Aug. 11, 1936; J. M. YOUNGER 2,050,597

' DEHYDRATOR Filed Feb. 7, 1954 2 Sheets-Sheet l Aug. 11, 1936;

J. M. YQUNGER DEHYDRATQR Filed Feb. 7, 1934 2 Sheets-Sheet 2 "ably-7 59%INVENTORI Patented Aug. 11, 1936 UNITED STATES DEHYDRATOR Joshua M.Younger, Alameda, Calif., assignor to James M. Thorp, Alameda, Calif.

Application February 7, 1934, Serial No. 710,046

5(Jlaims. (01. 34-39) The invention relates to hot air circulationdehydrators for drying fruit, vegetables and other foods, any or'all ofwhich will hereinafter be known as fruit". One object of the inventionis to provide a dehydrator wherein stacks of fruit trays are movedprogressively through, first a conditioning chamber, a drying chamberand lastly a finishing chamber; another object is to' utilize all theheat that is generated in the dehydrator, including that contained inthe humid air that is usually expelled into the atmosphere, togetherwith the heat absorbed by the finished fruit and by the trays containingsuch fruit; and a further object is to economize in the size of the hotair equipment by treating, alternately, first one half of the fruit,then the other half and by changing the direction of air'fiow atfrequent intervals so that all trays will receive a like treatmentduring their progress through the several chambers; still furtherobjects, some of which, with the foregoing, will be set forth in thefollowing specification and accompanying drawings, in which:

Figure l is a horizontal section on line ll of Fig. 2; Fig. 2, alongitudinal elevation in sec-' tion, on line 2-'l of Fig. 1; Fig. 3, asectional elevation, in reverse of Fig. 2 and on line 3-3 of Fig.l;'Fig. 4, a cross sectional elevation on line 44 of Fig. 1; Fig. 5, afragmentary end view of two fruit trays as superposed; and Fig. 6 across section of the trays on line 6-45 of Fig. 5.

Similar numerals denote similar parts throughout the several views:

I A dehydrator according to this inventionis disposed within a housingstructure, the walls of which are designated by the numeral I, the floor2 and the roof 3; the numeral 4 denotes the stack of fruit traysrepresenting the conditioning chamber; 5, 6 and l, the drying chamberand 8, the finishing chamber. By referring to Fig. 5, it is seen thatthe superposed trays form a solid wall on the sides thereof so that eachstack forms its own chamber to that extent. The'numeral 9 denotes theblower; Hi, the oscillating funnel discharge; the stack of radiatortubes; l2, the furnace; l3, the power room; M, the motor and I5 thecompensating weight to balance the oscillating discharge funnel; I0, 16and Ilia show plates set on an angle to divert the returning air flowtoward the radiator, these plates telescope, one part fixed to theoscillator and its mate 'to the roof and another pair below, one ofwhich is fixed to the floor.

In dehydrators according to this invention the furnace I2 is preferablyheated by fuel oil, the

heat fumes thereof are drawn through the radiator tubes II by theexhaust fan I'I, so as to traverse each tube alternately up and down asshown by arrows in Fig. 4.

For a clearer description it is -assumed that 5 several trucks carryingthe tray stacks 4 to 8 have reached their respective positions,progressively upon the tracks, that is, stack 4 is newly placed,

5 has occupied space 4 for say three hours and has been moved to 5, eachof the other stacks have 10 occupied the preceding space for the sametime, so that 8- has just been moved from I to its present position; 5to 8 have all been subjected to the 1 hot air treatment progressivelyand 8 is sufliciently dried to be cooled off, however,' the trays and1.5 the fruit therein have absorbed large quantities of heat at atemperature of approximately 150 degrees, whereas stack 4 is cold; 5, 6and I are in progressive stepsof drying; it is further assumed that thefurnace and radiators are in'heated con- 20 dition and that the bloweris forcing heated air through the lower half of the stacks 5, 6 and 1 asshown in Fig. 1 and in the depressed oscillating discharge Illa. Fig. 2;at this point description of the operation is taken up.

The air being forced through the lower half of the three center stacksis returned through the upper half, where it is spread out and flowsthrough the radiators, absorbing heat therefrom,

and thence to the blower intake where it is again forced into the traystacks and over thefruit absorbing moisture therefrom in its passage,thus a staturated condition of the air would resuit in time, butto avoidsuch saturation a portion of the air is continuouslydefiected by thebattle I8 into the upper half of stack 4, passlngout at the opening l9.Although this deflected air contains a high percentage of moisture italso con-- tains a great quantity of heat which would be lostifdischarged into the atmosphere in the 40 usual manner, instead it ishere utilized for conditioning the fruit at first stage. In practice itis found that slow initial warming of the fruit throughout, beforesubjecting it to the hot blast of air, prevents glazing of the surfacethus allowing the fruit to dry from the inside outwardly. As the humidair is taken out at one end, fresh air is being drawn in through stack 8where it absorbs heat from the now completely dry fruit and also fromthe heated trays in this process of cooling, the fresh air now passesthrough the radiator at 20 and on into the blower intake to be mixedwith the main volume of air to lower its humidity.

By directing the air blast through only half of the tray area andreturning through the other half the blower and heater equipment may beof smaller capacity than if the whole tray area were exposed at once.

The foregoing description and the drawings show the funnel blowerdischarge NJ in lower position Illa, with the return air flowing throughthe upper half, where in stack 5 the baffle I8 is shown cutting out ordeflecting a. portion of the air to the upper half of stack 4. Thefunnel discharge is to be oscillated at intervals of two or three timesper hour, according to the fruit being treated; obviously, a reverseflow of air through all the trays except 8 will result when thedischarge is raised as at Hlb, in dotted lines Fig. 2; the bafiie [8will then be closed and baiile 18a will be opened by the rod 2|, thenthe lower half of stack 4 will receive the deflected air while the upperhalf remains quiescent to absorb heat'from the still air. It will benoted that the rear and front stationary chambers 5a to la and 5b to 11)inclusive are extensions to the movable tray-formed chambers 5, 6 and I,and as the latter move forward their numbers change with location.

When these stacks have stood for the necessary time subject to severalchanges in air flow direction the doors are opened at both ends of thechambers and a fresh stack of trays is set against stack 4, then thewhole line is moved one space, thus stack 8 is moved into the open andstack 4, now conditioned, is set into the drying chamber and the newstack into the conditioning chamber, then the doors are closed.

The oscillating funnel is pivoted to the blower at 22, the other end israised and lowered by action of the shaft 23 and arm 24, one on eachside, and the connecting rods 25; it is counterbalanced by the weight [5which is supported by the rods 21 pivoted at top to the weight and atbottom to the arm 25, this arm, or crank; is fixed to the shaftdiametrically opposite the arm 24, both on the shaft 23, the weightbeing held by the sway arm 28 which is pivoted to the rear wall; a lever29 is keyed to the shaft end outside the wall at 30; it is obviousthat,in the position shown in Fig. 3, with arm 26 at upper dead center andarm 24 at lower dead center, that if the lever 29 is thrown up and overto 3| the discharge funnel ID will be raised to the position lfib andthe weight of the funnel will be balanced by the weight 15; thecontinuous opposite positions of these arms will compensate for thevarying leverage exerted by each in the traveled arc.

Baflies 32 and 33 are provided in the funnel I0, as in dotted lines Fig.1, as shown they are set so as to give a greater volume, or proportionof air into stack 5, a lesser volume to stack 6 and still less to stack1 but may be varied by the rods 34 and; 5a, 6a and 1a are the return airchambers for the three central stacks. The power room I3 is divided fromthe blower by a metal wall 36 and the alley 31 leading from thefinishing chamber is likewise closed in. Although the tray sides form asolid wall separating the stacks and virtually close in the conditioningchamber and the finishing chamber, doors 38 are provided' to furtherseal the housing.

Having thus described my invention in a manner understood by thoseskilled in the art, what I claim as new and desire to secure by LettersPatent is:

1. A fruit dehydrator, comprising a housing structure containing aconditioning chamber, a drying chamber and a finishing chamber, tracksleading through said structure and chambers, trucks upon the tracks,stacks of trays superposed upon the trucks, a furnace, and a radiatoradapted to carry fumes therefrom, a blower to discharge air into andthrough a portion of said stacks of trays and into a return air chamberwhere the air is returned through the other portion of the trays,through a radiator and to the blower intake, an oscillating blowerdischarg; pivoted to the blower whereby a change of air flow may be hadfrom one of said tray portions to the other portion in alternation,baflles to deflect the humid air into the conditioning chamber, a freshair inlet leading through said finishing chamber and said radiator tothe blower intake, bafiies within the oscillating discharge adapted toproportion the air between the drying 2 stacks, and means tocounterbalance and oscillate said blower discharge.

2. A fruit dehydrator consisting of housed trayformed drying chambersand a conditioning chamber, a blower having a funneled air dischargeadapted to oscillate alternately between the upper and lower portions ofsaid drying chambers, rear extension chambers adapted to return the airin alternation with said air discharge, front extension chambers locatedat the air discharge, baflies in said front extension chambers adaptedto be alternately opened and closed to deflect a portion of the returnair into the conditioning chamber.

3. A fruit dehydrator comprising a housing structure, a series oftray-formed chambers disposed therein, a blower having an oscillatingdischarge funnel, air heating means connected with said blower, shaft,crank and connecting rod means for oscillating the discharge funnel, andmounted upon the same shaft an opposed crank and connection rods,supporting a weight having sway-arm guides, in counter-balance to thefunnel discharge, and a lever fixed to the shaft of said crank formanual operation of said weight and said funnel.

4. A fruit dehydrator comprising a housing structure and a conditioningchamber disposed at the entrance side of the structure, a series ofdrying chambers adjoining the conditioning chamber, superposed bafflesmounted in the front extension to the first of said series of dryingchambers, and means for operating said baffles whereby a portion of thereturn air from the drying chamber is deflected into and through theupper or the lower portion of the conditioning chamber.

5. A fruit dehydrator comprising a housing structure, tracks laidlaterally of the structure, trucks loaded with superposed trays upon thetracks, a blower with pivoted funnel discharge adapted to force heatedair through a portion of the trays, air chambers disposed opposite theblower discharge and adapted to return said heated air through anotherportion of the trays to the blower intake, adjustable baiiies withinsaid pivoted funnel discharge adapted to proportion the air between theseveral tray stacks, and

I manual means for oscillating the discharge funnel.

JOSHUA M. YOUNGER.

